It is axiomatic that the efficiency of a gasoline-powered engine can be improved by a more complete burning of the air-fuel mixture. With this realization, engine designers have attempted to maximize fuel atomization by constructing intake manifolds and combustion chambers that impart turbulence to the air/fuel mixture both before and during ignition.
Heating the fuel prior to combustion can also greatly speed the atomization process. Ideally, the fuel should be heated before it is mixed with air. Heating the air reduces engine efficiency by making the air less dense and, hence, less oxygen rich per unit volume.
It has also long been known that a liquid injection system increases fuel efficiency, allows higher power output by decreasing the tendency of the fuel to detonate before the spark plugs fire, and promotes a cleaner combustion process resulting in reduced deposit formation in the combustion chambers.